In the invention of my above-mentioned application, improvements have been conceived relating to cooled horizontal-axle grinders for the predispersion of solids in liquids of high or medium viscosity, which grinders are of the type which incorporate grinding bodies, for example balls, which are generally introduced through the treated product inlet port and extracted through an outlet situated in the lower part of the chamber, where this grinding chamber is provided with a double wall for the corresponding cooling mechanism and, in turn, with a circulating pump for the liquid coolant in question, and also incorporates an axle or shaft on which are mounted corresponding interchangeable agitator discs situated at predetermined distances from each other by means of separators, where this shaft is driven by a motor through a suitable transmission system and speed regulator; the system also contains a pump and corresponding flow regulator which impel the product being treated.
The improvements which are the object of the invention in the above-mentioned application relate to an element acting as a filter, which retains the grinding bodies in the interior of the grinding chamber, while giving passage exclusively to the product as it is treated. This filter comprises a sieve mounted coaxially with and around the axle and joined to it in such a way that the sieve rotates with the axle, thereby retaining the grinding balls in the grinding chamber while permitting the finely ground product to flow through the sieve into an extraction chamber for discharge to the exterior.
The improvements which are the object of this invention refer to a new separating system between the grinding chamber and the extraction chamber for the ground product, which separating system is to be substituted for the conventional seal assembly used in the grinder of my earlier application. This new separating system consists essentially of a static perforated metal disc and a coaxial metal ring which rotates with respect to it, and which is joined to the sieve or filter element which rotates with the grinder axle. The separation or spacing between both elements, the static perforated disc and the coaxial ring, is constant and is equal to or less than the separation or the pass diameter of the sieve, and may lie between 0.2 and 1 mm.
The following advantages, with respect to the conventional seal assembly represented in my earlier application, are obtained with this new system:
1. Wear due to abrasion is eliminated.
2. The ground product output area is increased.
3. The pressure in the grinding chamber is reduced.
4. The surface is smoother, which makes cleaning easier.